Slider for slide fasteners



H. ERD'MANN SLIDER FoR SLIDE FAsTENERs Dec. 23, 1952 s sheets-sheet 1 Filed March 27, 1951 mvENToR n N N N A M T D R A El s N. A H

Dec. 23, 1952 H. ERDMANN 2,622,297

SLIDER FOR .SLIDE FASTENERS Filed March 27, 1951 3 Sheets-'Sheet 2 mvENToR HANS ERDMANN,

BY W ATT RNEY Patented Dec. 23, 1952 2,622,297 SLIDER FOR SLIDE` FASTENERS Hans Erdmann, Maplewood, N. J., assignor to Waldes Kohinoor, Inc., Long Island City, N. Y., a corporation of New York f Application March 27, 1951seria1No, 217,776

l Claims.

This invention relates to improvements in vsliders for slide fasteners, and more particularly to an improved automatic lock slider of the class disclosed in my copending application Serial No. 136,689, filed January 4, 1950.

According to one' form of automatic lock slider disclosed .in my aforesaid application, the locking spring is shaped generally as a U, having one arm seated and anchored in a recess provided in the underface of the upper slider Wing, the other or lifting arm extending through an opening in the upper wing into the eye dened by the bail and front face of said wing so as to overlie the trunnions forming the pivot for the slider pull tab. Lateral displacement bothV of the locking spring and the pull tab is prevented by a rib extending fromV the inner surface of the bail into the gap provided in said other arm due to its forked or bifurcated formation. Although a slider as aforesaid operates on the whole satisfactorily, vit is open to certain objections in use, the correction of .which is desirable.

For example, there is the danger that a forceful pull exerted by the pull tab on the lifting arm of the spring may tend to impair the elasticity of the latter, and since even a slight permanent set could greatly affect the functioning of the locking spring, the advisability of preventing a too great strain being imparted thereon becomes apparent. Furthermore, when the pull tab is moved infastener closing direction, there is the possibility of the trunnions lodging in the'space between the end of the spring lifting arm and the bail, and when such occurs, it is difcult if not impossible to free the pull tab for further operation of the slider.

A similar diculty may arise near the opposite end of the bail into which the trunnions move in the down or fastener-opening movement of the slider. As in the preferred form of spring, the upper or lifting arm thereof extends at a rather sharp angle from its base or spring-leaf arm, the pull tab trunnions may become'jammed Within this sharply angled space and fail to re-assume their normal position when the pull tab is released following movement of the slider in fastener-opening direction. Such can result in the locking pin being held out of its locking position, so that it cannot perform its locking function upon release of the pull tab, as intended.

It is a principal object of the invention to overcome the aforesaid difficulties of a lock slider according to one form disclosed in Ymy prior application Serial No. 136,689, through the provision of means for preventing jamming of the pull tab trunnions in either of the end positions of their movement, which is at the same time effective to make impossible a permanent deformation of the locking spring.

More particularly, the invention contemplates and provides a locking slider of the aforesaid class incorporating means which insure movement of the pull tab trunnions in a substantially straight line path which isv parallel to the outer face of the slider front wing, so that the trunnions cannot at any point of their travel be raised an amount which would result in undue strain being imposed on the locking spring. This desirable feature of the invention is achieved by so forming the -bail that it confines the pull tab trunnions lto substantially straight line movement in ya direction parallel to the outer face of the slider front wing.

A further important object of the invention is to so design the pull tab trunnions that they cannot jam in the angular space between the leaf-spring and lifting arms of the locking spring consequent to pull on the pull tab in fastener opening direction, with the result that movement of the trunnions to their normal position upon release 4of the tab is assured.

Yet another object of the invention is to provide the requisite formation of locking spring conditioned. to the new construction of the bail for insuring substantially straight line movement of the trunnions. According to this feature of the invention, the lifting arm portion of the locking spring, rather than being forked or bifurcated as shown in my prior application aforesaid, is formed as a single arm which is offset to one side of the longitudinal centerline,

of the slider so that the new bail construction aforesaid in nowise interferes with the normal action of the locking spring.

Still another object of the invention is to so form the locking spring that it has increased stiffness in longitudinal direction without impairing the transverse flexibility of its leafspring arm.

The above and other objects and advantages of the improved lock slider will be apparent from the following detailed description accompanied by drawings, in which- Fig. 1 is a side elevation of the improved 4fastener whose pull tab is shown to be slightly raised for clarity of disclosure; A

Fig. 2 is a transverse section taking' along line 2-2 of Fig. 1, which affords a plan view looking into the underface of the slider front wing;

Fig. 3 is a longitudinal section taken through lthe slider illustrated in Fig. 1, it being noted that this view and subsequent views are turned 180 with relation to the Fig. l View Fig. 4 is a section taken along line -li of Fig. 3;

Fig. 5 is a perspective view illustrating the form of locking spring employed in the slider according to the figures aforesaid;

Fig. 6 is a section similar to that shown in Fig. 3, but illustrating the position of the trunnions upon downward pull being applied to the pull tab;

Fig. 7 is a similar view illustrating the normal position which the pull tab trunnions assume upon release of downward pull on the pull tab;

Figs. 8, 10 and 12 are sectional views similar to Fig. 3 which illustrate modified forms of locking spring; and

EFigs. 9, 11 and 13 are perspective views of the locking springs employed in the modified sliders illustrated in Figs. 8, l0 and l2, respectively.

Referring to Figs. 1 7, inclusive, of the drawings, a locking slider according to the invention employs `a conventional slider body comprising a front wing ID and a rear wing I I both having side flanges I2, I3 and being connected by 9, neck portion I4 having a U-shaped indentation I5, which latter .also serves as a divider for separating the interengaged slide fastener elements (shown in dotted lines, Fig. 3)` when pull in fastener opening direction is applied to the pull tab It. A bail I'I is struck out from the material of the front Wing Il), leaving an opening i8 in the front wing having a broadened portion Ia (Fig. 3) to accommodate the locking spring I9. As with the locking spring of my aforesaid application Serial No. 136,689, the locking spring I9 is adapted to be inserted from beneath the front wing ii) and may be anchored by means of transversely extending portions 26, 2l formed integrally with and underlying one'end of the lower arm 22 of the spring (Fig. 5) and which are seated and secured in'recesses 23, 24 in the underface of the front wing. The lower spring arm 22 thus acts as a leaf-spring, and by virtue of Vits aforesaid mounting is disposed substantially in the plane of the slider front wing IU.

As best seen in Figs. 2 and 5, the free end of the leaf-spring arm 22 of the locking spring is widened as at 25, and is bent upwardly on itself in its widened portion so as to form an inclined lifting arm 26 which extends into the eye of the bail I'I. The lifting arm 25 is abruptly reduced in width and is moreover offset to the longitudinal centerline of the base or leaf-spring arm of the spring I9 which coincides with the longitudinal centerline of the slider, the purpose of this offsetting to be hereinafter explained. Near its free end, the arm 22 of the locking spring is provided with a depending locking pin 2 which, in the normal position of the spring, enters the space between two adjacent fastener elements shownv in dotted lines (Figs. 3 and 6) thereby to lock the slider against unintentional movement lengthwise of the fastener.

The pull tab i6 is pivotally connected to the slider body by means of trunnions 29, 3i) which project from opposite directions into the eye ofthe bail Il. Due to the elongation .of the eye, the pull tab is also permitted limited longitudinal movement with respect to the slider. By reference to Fig. 4, it will be seen that the lifting arm 26 of the locking spring I9 overlies one of the pull tab trunnions, shown to be the trunnion 2-9, the arrangement being such that when pull is exerted on the pull tab I5 in fastener-opening direction, the trunnion 28 engages the undersurface of the spring lifting arm with ra camming action, thereby to lift the locking pin 21 out of locking engagement with the two adjacent fastener elements with which it normally interlocks.

As has been pointed out in the foregoing, it is desirable that the longitudinal movement of the pull tab trunnions be confined to a substantially straight line movement in a path which is parallel to the outer face of the slider front wing Ill, so that the trunnion 29 can never move away V.from said'face in outward direction an amount that might impose severe strain on the locking spring i2. To attain this desirable objective, the eye of the bail is subdivided longitudinally by means of a rib 32 depending inwardly from the inner surface of the bail, the rib thus dividing ce eye into two longitudinal chambers or compartments. One eye compartment, i. e. -that to the left of the rib 32 (Fig. 4) has normal depth so that it may accommodate the lifting arm 26 of the locking spring and the trunnion 29 which it overlies; whereas the other eye chamber, i. e. that to the right of the rib 32 has reduced dep-th which is only slightly in excess of the major diameter of the trunnion 30, so that while the pull tab It may be freely lifted and lowered and partake of its longitudinal travel withrrespect to the eye, the trunnion 3e and hence the trunnion 25 are confined -against any substantial movement away from the outer face of the slider front wing IQ. This confining -action on` trunnions is achieved by thickening the bail to the right of the rib 32 so thatI its inner4 surface, which defines the front or outer side of the righthand eye compartment, forms a straight track 33 disposed parallel to the outer face of the front wing I0 and which is spaced from said outer face :a distance corresponding to the major dimension of the trunnion 30. Thus, whiletrunnion Si! is free to travel longitudinally in the right-hand eye compartment, any movement thereof in outward direction is positively prevented by its engagement on the track surface 33 of the bail. Accordingly, any danger of overstressing the locking spring I9 is positively avoided.

In addition to the function of the small depth eye chamber for the trunnion 30 in preventing overstressing of the locking spring as aforesaid, said chamber also serves in preventing both the trunnions 29, 30, due to their minute dimensions, from entering the space between end of the lifting arm 26 and the bail and becoming lodged therein. This results from the fact that the bail track 33 positively prevents either trunnion from moving outwardly of the front wing an amount such that the trunnions can enter the aforesaid space.

In my previous locking slider, there was also the possibility of the trunnions jamming and becoming stuck in the angular space between the leaf-spring and lifting arms of the locking spring following a downward pull on the slider. To overcome this objection, both the trunnions r29, 30, and particularly the trunnion 29, is provided with elongated oval cross section, the major axis of the section extending in the plane of the pull tab, as best seen in Figs. 6 and 7. Accordingly, when downward pull is exerted on the pull tab to move the slider in fastener openingdirection, the trunnion '29 moves into the angular space between .the arms-of the locking spring and effects lifting Vof the locking pin in the usual manner. However,

due to its oval cross section, the trunnion 29 cannot b1nd or jam in said space, as will be clear from an analysis of Fig. 6. Accordingly, upon ydownward pull being interrupted,.the trunnion 29 will return to its normal position illustrated in Fig. 7, undervthe bias'of the leaf-spring arm 22 of the locking spring. This inability of the trunnion 29 to lodge in the spring without return movement is -aided by displacing the axis of the `trunnion 29 vslightly below that of the trunnion ing'arm is intended to operate only within the left-hand eye chamber, as shown in Fig. 4. In addition to subdividing the eye chamber formed by the bail into two longitudinal compartments as aforesaid, the rib 32 also functions to prevent any lateral displacement both of the locking spring and of the pull tab as well.

To increase transverse flexibility and longitudinal stiffness of the locking spring I9, the

transversely extending portions 20, '2| thereof which seat in the underface recesses 23, 24 of the slider front wing are disposed as an underlying extension of the leaf arm 22, as shown in Fig. 5. This arrangement, taken with the widening of the free end portion of the leaf arm, results in the latter having increased longitudinal stiffness accompanied by transverse flexibility at the line of bend between the spring leaf 22 and the underlying transverse portions 20, 2| thereof. This desirable objective is also attained by the locking spring constructions as shown in Figs. 8-13, inclusive. Referring to Fig. 9, illustrating the modied spring employed in the Fig. 8 slider, it will be seen that the anchoring end of the spring leaf 22a is provided with double bends which connect it with the transversely extending portions 20a, 2 la. In the form of locking spring illustrated in Fig. 1l, and which is employed in the Fig. 10 form of slider, the leaf-spring arm 22h of the locking spring is connected to its transversely extending securing portions 29h, 2lb by a wraparound connecting portion.

It is also possible to arrange the transversely extending anchoring portions of the spring in the plane of the leaf-spring arm as indicated in Fig. 13, which illustrates a locking spring of the type employed in the Fig. 12 form of slider. In this form the leaf-spring arm 22o of the locking spring is connected to its transversely extending securing portions 20c, 2 l c by means of a vertically disposed bend, which maintains the transversely extending portions in the plane of the leaf-spring arm. In all of the aforesaid spring forms, the leaf-spring arm has relatively great longitudinal rigidity, but can be readily flexed transversely at some point between the leaf-spring arm proper and its transversely extending ends which are of course rigidly affixed to the slider front wing.

Without further analysis it will be appreciated that a locking slider according to the various forms described and illustrated herein achieves the desirable objectives set forth in the foregoing.

However,"as many changes could be'made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A lock slider for slide fasteners comprising front and rear wings connected in spaced relation by a neck portion extending between the upper ends of the wings, a bail extending from the front wing Aand forming therewith an elongated eye, a pull tab having trunnions extending into the eye adapted both for turning movement therein and for limited travel along the length of the eye, a locking spring including a leaf arm anchored at its upper end to lie substantially in the plane of ,the front wing, a locking pin carried adjacent the free end of the leaf arm adapted normally to project into Vthe space between said wings, and an inclined lifting arm extending at an acute angle from the free end of the leaf arm into the eye, said lifting arm being offset to one side of the longitudinal center line of .the slider and overlying the one of said trunnions disposed to the same side of said center line, said eye being subdivided into two longitudinal eye-chambers, one chamber receiving and having depth to accommodate the offset lifting arm and said one trunnion which it overlies, and the other chamber receiving said other trunnion and having lesser depth than said one chamber and which is such as vto coni-lne said other trunnion to substantially straight-line travel along the length of said eye and in a plane which is parallel to the outer face of the slider front wing.

2. A lock slider for slide fasteners comprising front and rear wings connected in spaced relation by a neck portion extending between the upper ends of the wings, a bail extending from the front wing and forming therewith an elongated eye, a pull tab having trunnions extending into the eye adapted both for turning movement therein and for limited travel along the length of the eye, a, locking spring including a leaf arm v anchored at its upper end to lie substantially in the plane of the front wing, a locking pin carried adjacent the free end of the leaf arm adapted normally to project into the space between said wings, andan inclined lifting arm extending at an acute angle from the free end of the leaf arm into the eye and outwardly of said trunnions, a rib extending from the bail into said eye and subdividing it into two elongated eye chambers for said trunnions which are disposed to the sides of the longitudinal center line of the slider, the lifting arm of Vthe locking spring being oifset from the slider center line to extend into one of said chambers and to overlie only the one trunnion extending thereinto, the other chamber having depth corresponding to the diameter of the other trunnion thereby to confine travel of the trunnions along the length of the eye to substantially straight-line travel in a plane parallel to the outer face of the front wing.

3. A lock slider for slide fasteners comprising front and rear wings connected in spaced relation by a neck portion extending between the upper ends of the wings, a bail extending from the front wing and forming therewith an elongated eye, a pull tab having trunnions extending into the eye adapted both for turning movement therein and for limited travel along the length of the eye, a locking spring including a -leaf arm anchored at its upper end to lie substantially in the plane of the front Wing, a locking pin carried adjacent the free end of the leaf arm adapted normally to project into the space between said wings, and an inclined lifting arm extending at an acute angle from the free end of the leaf arm into the eye and outwardly of said trunnions, a rib disposed on the longitudinal center line of the bail and extending into the eye thereof to subdivide said eye into two elongated trunnionreceiving eye chambers, the lifting arm of the locking spring `being offset from the center line thereof to extend into one of said chambers and to overlie only the one trunnion extending thereinto, the wall of the bail defining the front side of the other eye-chamber being thickened and formed straight to provide an outer guide track for the other trunnion which is spaced from the outer face of the slider front Wing an amount corresponding to the diameter of the other trunnion, whereby travel of trunnions along the length of the eye is confined to substantially straight-line travel in a plane parallel to said outer face of said front wing.

4. A lock slider as set forth in claim 3,'wherein at leastthe one trunnion underlying the lifting arm of the locking spring has flattened section whose major dimension extends in the plane of the pull tab, whereby it cannot jam in the angular space between the leaf and lifting arms of said locking spring consequent to downward pull being exerted on the pull tab.

HANS ERDMANN.

REFERENCES CITED The following references are'of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,936,096 Norton Nov. 21, 1933 2,053,463 Conlin Sept. 8, 1936 2,373,523 Winterhalter Apr. 10, 1945 FOREIGN PATENTS Number Country Date 216,674 Switzerland of 1942 417,781 Great Britain of 1934 532,431 Great Britain of 1941 

